1. Field of the Invention
The present invention relates generally to medical devices and methods. More particularly, the present invention relates to an intraluminal catheter configured to stow two or more treatment catheters and/or guidewires and allow for distal advancement of one such catheter or guidewire at a time.
The use of a dual lumen catheter for introducing and exchanging guidewires and therapeutic or imaging catheters has been proposed. See, for example, U.S. Pat. No. 5,203,338 and U.S. Patent Publication No. 2008/0154345. The systems described in each of these documents use an outer catheter or sheath having two proximal lumens connected to a single reduced-diameter distal lumen for delivering and exchanging guidewires, therapeutic catheters, and imaging catheters. Typically, a single guidewire is stored in one proximal lumen while a single imaging or therapeutic catheter is stored in the other proximal lumen. The dual lumen catheter may be positioned at a target site within the vasculature of the body lumen, and the guidewire and catheter selectively advanced through the distal lumen when needed.
While effective, the use of such storage catheters having two lumens in the proximal section is disadvantageous in several respects. First, the formation of two or more discrete lumens in the proximal portion usually results in a larger diameter. While acceptable in many applications, in some vascular and cardiovascular applications, it is desirable to reduce even the proximal diameter as much as possible. Second, the need to fabricate two or more discrete lumens in the proximal portion complicates the fabrication of the catheter. Additionally, the initial formation of discrete proximal lumens with fixed dimensions limits the ability to introduce therapeutic and imaging catheters which exceed the fixed dimensions.
For these reasons, it would be desirable to provide storage and exchange catheters which have reduced profile proximal portions, which are easier to fabricate, and which permit increased flexibility in the range of catheters and guidewires which be stored and selectively introduced. At least some of these objectives will be met by the inventions described and claimed below.
2. Description of the Background Art
U.S. Pat. Nos. 5,203,338; 5,665,533; 5,976,093; 5,997,523; 6,234,971; 6,730,037; 7,160,724; and WO 01/66698 and WO 92/11055 describe dual lumen catheters for holding and exchanging a guidewire and an imaging core, where a distal portion of the body comprises a reduced diameter single lumen segment. US 2008/0154345 describes a method and system for advancing a laser catheter across an occlusion using a catheter body having a dual lumen proximal portion and a single lumen distal portion. See also U.S. Patent Publication Nos. 2008/0172033; 2008/0009770; 2005/0245962; and U.S. Pat. Nos. 7,018,358 and 6,106,487.